HelloI am using Linux Mint 13 XFCE for a while and I have this annoying problem

When I am right clicking (on gedit for example), the popup menu appears normally. However it's possible to select an option, by clicking the right button on the mouse too.

This does not look a big deal, but when I am for example in the terminal and I want to paste a command, when the popup menu appears (with a right click) immediately selects the first option (open terminal) and a new terminal appearsThis is annoying, because I must keep the right button down, move the cursor to the desired option and then release it

Is it possible to set the mouse in such a way to select an option in a popup menu only with left click?